Use of lung-thorax transverse area ratio in the antenatal evaluation of lung hypoplasia in congenital diaphragmatic hernia.

For evaluation of lung hypoplasia in congenital diaphragmatic hernia (CDH), we measured lung-thorax transverse area ratio (LT ratio), which was defined as the area of bilateral lung profiles divided by the profile area of thorax at the level of the four-chamber view of the heart, using fetal ultrasonography. LT ratio in cases with CDH was lower than that in the control group and related well to the postnatal respiratory condition. Measurement of LT ratio using fetal ultrasonography may be useful in predicting the degree of lung hypoplasia in fetuses with CDH.